Limits...
Ozone-Induced Rice Grain Yield Loss Is Triggered via a Change in Panicle Morphology That Is Controlled by ABERRANT PANICLE ORGANIZATION 1 Gene.

Tsukahara K, Sawada H, Kohno Y, Matsuura T, Mori IC, Terao T, Ioki M, Tamaoki M - PLoS ONE (2015)

Bottom Line: The Habataki allele of the APO1 locus in a near-isogenic line also resulted in grain yield loss upon ozone exposure, suggesting APO1 involvement in ozone-induced yield loss.Only a few differences in the APO1 amino acid sequences were detected between the cultivars, but the APO1 transcript level was oppositely regulated by ozone exposure: i.e., it increased in Sasanishiki and decreased in Habataki.These data indicate that ozone-induced grain yield loss in Habataki is caused by a reduction in the APO1 transcript level through an increase in the levels of phytohormones that reduce leaf damage.

View Article: PubMed Central - PubMed

Affiliation: Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan.

ABSTRACT
Rice grain yield is predicted to decrease in the future because of an increase in tropospheric ozone concentration. However, the underlying mechanisms are unclear. Here, we investigated the responses to ozone of two rice (Oryza Sativa L.) cultivars, Sasanishiki and Habataki. Sasanishiki showed ozone-induced leaf injury, but no grain yield loss. By contrast, Habataki showed grain yield loss with minimal leaf injury. A QTL associated with grain yield loss caused by ozone was identified in Sasanishiki/Habataki chromosome segment substitution lines and included the ABERRANT PANICLE ORGANIZATION 1 (APO1) gene. The Habataki allele of the APO1 locus in a near-isogenic line also resulted in grain yield loss upon ozone exposure, suggesting APO1 involvement in ozone-induced yield loss. Only a few differences in the APO1 amino acid sequences were detected between the cultivars, but the APO1 transcript level was oppositely regulated by ozone exposure: i.e., it increased in Sasanishiki and decreased in Habataki. Interestingly, the levels of some phytohormones (jasmonic acid, jasmonoyl-L-isoleucine, and abscisic acid) known to be involved in attenuation of ozone-induced leaf injury tended to decrease in Sasanishiki but to increase in Habataki upon ozone exposure. These data indicate that ozone-induced grain yield loss in Habataki is caused by a reduction in the APO1 transcript level through an increase in the levels of phytohormones that reduce leaf damage.

Show MeSH

Related in: MedlinePlus

Effects of elevated ozone on two rice cultivars, Sasanishiki and Habataki.(A) Changes in grain yield in 2009 and 2010. (B) Changes in the number of primary rachis branches in 2009 and 2010. Values are mean ± SD (n = 20). Error bars indicate SD; n.s., not significant; *P<0.1; **P<0.05 (Student’s t-test). AA, ambient air; O3, elevated ozone; Sasa, Sasanishiki; Haba, Habataki. (C) Typical panicles of Habataki grown under ambient air (left) or elevated ozone (right). Yellow circles indicateidentify each primary rachis branches. Scale bar = 5 cm.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4414449&req=5

pone.0123308.g001: Effects of elevated ozone on two rice cultivars, Sasanishiki and Habataki.(A) Changes in grain yield in 2009 and 2010. (B) Changes in the number of primary rachis branches in 2009 and 2010. Values are mean ± SD (n = 20). Error bars indicate SD; n.s., not significant; *P<0.1; **P<0.05 (Student’s t-test). AA, ambient air; O3, elevated ozone; Sasa, Sasanishiki; Haba, Habataki. (C) Typical panicles of Habataki grown under ambient air (left) or elevated ozone (right). Yellow circles indicateidentify each primary rachis branches. Scale bar = 5 cm.

Mentions: We first investigated changes in vegetative and reproductive traits caused by ozone exposure in Sasanishiki and Habataki. In Habataki, ozone exposure (approximately twice the concentration in the ambient air) reduced grain yield by 19% (P = 0.038) in 2009 and by 12% (P = 0.085) in 2010 relative to control plants (Fig 1A), although no or weak leaf injury was detected (Table B in S1 File) [18]. By contrast, no ozone-induced reduction of grain yield was observed in Sasanishiki. Interestingly, visible leaf injury appeared in ozone-exposed Sasanishiki (Table B in S1 File) [18]. The number of primary rachis branches was significantly decreased (by 17%) upon ozone exposure in Habataki but not in Sasanishiki (Fig 1B and 1C). Ozone-induced changes in other vegetative or reproductive traits (biomass, culm length, panicle number per plant, panicle length, sterile grain number, total grain number, number of filled grains per panicle, and filling rate) were observed in both cultivars (Table B in S1 File). However, ozone-induced changes in these traits were detected only in one of the two years in both cultivars. Therefore, we consider only the number of primary rachis branches and grain yield as traits affected by ozone in Habataki but not in Sasanishiki, and these traits were assessed further.


Ozone-Induced Rice Grain Yield Loss Is Triggered via a Change in Panicle Morphology That Is Controlled by ABERRANT PANICLE ORGANIZATION 1 Gene.

Tsukahara K, Sawada H, Kohno Y, Matsuura T, Mori IC, Terao T, Ioki M, Tamaoki M - PLoS ONE (2015)

Effects of elevated ozone on two rice cultivars, Sasanishiki and Habataki.(A) Changes in grain yield in 2009 and 2010. (B) Changes in the number of primary rachis branches in 2009 and 2010. Values are mean ± SD (n = 20). Error bars indicate SD; n.s., not significant; *P<0.1; **P<0.05 (Student’s t-test). AA, ambient air; O3, elevated ozone; Sasa, Sasanishiki; Haba, Habataki. (C) Typical panicles of Habataki grown under ambient air (left) or elevated ozone (right). Yellow circles indicateidentify each primary rachis branches. Scale bar = 5 cm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414449&req=5

pone.0123308.g001: Effects of elevated ozone on two rice cultivars, Sasanishiki and Habataki.(A) Changes in grain yield in 2009 and 2010. (B) Changes in the number of primary rachis branches in 2009 and 2010. Values are mean ± SD (n = 20). Error bars indicate SD; n.s., not significant; *P<0.1; **P<0.05 (Student’s t-test). AA, ambient air; O3, elevated ozone; Sasa, Sasanishiki; Haba, Habataki. (C) Typical panicles of Habataki grown under ambient air (left) or elevated ozone (right). Yellow circles indicateidentify each primary rachis branches. Scale bar = 5 cm.
Mentions: We first investigated changes in vegetative and reproductive traits caused by ozone exposure in Sasanishiki and Habataki. In Habataki, ozone exposure (approximately twice the concentration in the ambient air) reduced grain yield by 19% (P = 0.038) in 2009 and by 12% (P = 0.085) in 2010 relative to control plants (Fig 1A), although no or weak leaf injury was detected (Table B in S1 File) [18]. By contrast, no ozone-induced reduction of grain yield was observed in Sasanishiki. Interestingly, visible leaf injury appeared in ozone-exposed Sasanishiki (Table B in S1 File) [18]. The number of primary rachis branches was significantly decreased (by 17%) upon ozone exposure in Habataki but not in Sasanishiki (Fig 1B and 1C). Ozone-induced changes in other vegetative or reproductive traits (biomass, culm length, panicle number per plant, panicle length, sterile grain number, total grain number, number of filled grains per panicle, and filling rate) were observed in both cultivars (Table B in S1 File). However, ozone-induced changes in these traits were detected only in one of the two years in both cultivars. Therefore, we consider only the number of primary rachis branches and grain yield as traits affected by ozone in Habataki but not in Sasanishiki, and these traits were assessed further.

Bottom Line: The Habataki allele of the APO1 locus in a near-isogenic line also resulted in grain yield loss upon ozone exposure, suggesting APO1 involvement in ozone-induced yield loss.Only a few differences in the APO1 amino acid sequences were detected between the cultivars, but the APO1 transcript level was oppositely regulated by ozone exposure: i.e., it increased in Sasanishiki and decreased in Habataki.These data indicate that ozone-induced grain yield loss in Habataki is caused by a reduction in the APO1 transcript level through an increase in the levels of phytohormones that reduce leaf damage.

View Article: PubMed Central - PubMed

Affiliation: Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan.

ABSTRACT
Rice grain yield is predicted to decrease in the future because of an increase in tropospheric ozone concentration. However, the underlying mechanisms are unclear. Here, we investigated the responses to ozone of two rice (Oryza Sativa L.) cultivars, Sasanishiki and Habataki. Sasanishiki showed ozone-induced leaf injury, but no grain yield loss. By contrast, Habataki showed grain yield loss with minimal leaf injury. A QTL associated with grain yield loss caused by ozone was identified in Sasanishiki/Habataki chromosome segment substitution lines and included the ABERRANT PANICLE ORGANIZATION 1 (APO1) gene. The Habataki allele of the APO1 locus in a near-isogenic line also resulted in grain yield loss upon ozone exposure, suggesting APO1 involvement in ozone-induced yield loss. Only a few differences in the APO1 amino acid sequences were detected between the cultivars, but the APO1 transcript level was oppositely regulated by ozone exposure: i.e., it increased in Sasanishiki and decreased in Habataki. Interestingly, the levels of some phytohormones (jasmonic acid, jasmonoyl-L-isoleucine, and abscisic acid) known to be involved in attenuation of ozone-induced leaf injury tended to decrease in Sasanishiki but to increase in Habataki upon ozone exposure. These data indicate that ozone-induced grain yield loss in Habataki is caused by a reduction in the APO1 transcript level through an increase in the levels of phytohormones that reduce leaf damage.

Show MeSH
Related in: MedlinePlus